Multilumen venous catheters are advantageous as they eliminate the need for separate catheters for monitoring a patient's blood pressure and infusing or withdrawing fluids from a patient thereby decreasing the possibility of patient discomfort and possible infection inherent with the insertion of several single lumen catheters into the patient. Maintaining fluids separately is particularly critical when the fluids employed are chemically incompatible or when cross contamination of fluids is to be avoided.
Conventional multilumen venous catheters have a plurality of lumens which may be integrally formed in a single catheter tube. The lumens in conventional multilumen catheters extend throughout the length of the catheter tube and are usually arranged in a side-by-side configuration within a catheter tube as shown in cross-section in FIG. 1. However, this configuration limits the effective cross-sectional area of each of the lumens present within the multilumen catheter as the wall sections between each of the lumens take up a significant amount of the overall area of the catheter tube. Therefore, the amount of fluid flow in each of the lumens is limited by the catheter tube diameter.
Furthermore, conventional multilumen catheters may be potentially hazardous to the patient as they provide a direct conduit for blood to leave the patient, and have been responsible for causing substantial blood loss. Some conventional multilumen catheters are equipped with extension tubing coupled to valves which close the separate lumens to blood flow when the lumens are not in use. However, these valves are not always reliable.
Another disadvantage of conventional multilumen catheters is that they are usually made in one piece from a material of limited flexibility and softness. Thus, the patient may experience increased trauma and discomfort from a relatively rigid catheter as the catheter is inserted in a vein, and damage to the inner lining of the vein may also result from such relatively rigid catheters.
Therefore, it would be desirable to have a multilumen catheter which overcomes the above-described disadvantages, which is economical to produce, and which is compatible with existing medical equipment used with conventional multiple lumen catheters.